1. Field of the Invention
The present invention relates to polysilazane, a method of synthesizing the polysilazane, a composition for manufacturing a semiconductor device, and a method of manufacturing a semiconductor device using the composition.
2. Description of Related Art
In general, a semiconductor device may include patterns formed on a silicon wafer, for example, patterns such as a transistor, a bit line, a capacitor, a metal line, and the like. Because these patterns may be conductive, an insulating layer may be formed between these patterns. A process for forming the insulating layer may include a Premetal Dielectric (PMD) process for insulating between the transistor and bit line, between the bit line and capacitor, and between the capacitor and metal line, an Interlayer Dielectric (ILD) process for insulating between metal lines, and a Shallow Trench Isolation (STI) process for filling a groove such as a trench. The STI process will be hereunder described in detail.
As an interval between these patterns becomes narrow due to high-integration of the semiconductor device, a width of the trench accordingly becomes narrow. Currently, the trench having a width of about 60 nm or less may be required according to a design rule. In this case, problems may be created on a process for manufacturing the semiconductor device. For example, in a process for manufacturing a semiconductor device including a trench having a width of about 60 nm or more according to the design rule, a silicon oxide layer may be formed inside the trench using a Chemical Vapor Deposition (CVD) method. However, in a process for manufacturing the semiconductor device including the trench having a width of about 60 nm or less according to the design rule, pores may be disadvantageously formed inside the trench when using the CVD method for the purpose of forming the silicon oxide layer inside the trench.
In order to overcome the above-mentioned problem, techniques that may generate the silicon oxide layer using a composition for manufacturing the semiconductor device, and enable spin coating have been developed. A composition for manufacturing the semiconductor device including polysilazane may be most gaining attention as the composition for manufacturing the semiconductor device, and accordingly a study for the composition including polysilazane has been actively made. Most of the polysilazane included in the composition for manufacturing the semiconductor device may be synthesized through a reaction between ammonia and dichlorosilane within a reaction solvent. However, the polysilazane obtained through the above-mentioned reaction may have disadvantages that a molecular weight of the polysilazane is extraordinarily small or a yield of the polysilazane is low. When the molecular weight of the polysilazane is extraordinarily small, a film thickness may be disadvantageously formed as being extraordinarily thin in a spin coating process using the composition including the polysilazane, or coating loss in a heating process may be great.
Accordingly, a composition for manufacturing the semiconductor device including polysilazane whose molecular weight is larger may be needed. However, when the molecular weight of the polysilazane is extraordinarily great, a trench filling property by which the polysilazane is filled in the trench may be deteriorated, and which may result in generation of pores inside the trench.